Lassa Fever Research Articles

An ordered mesoporous carbon-silica hybrid for the detection of the antiviral drug ribavirin in clinical samples.

Ribavirin (RIB) is widely used for the treatment of viral diseases such as herpes, hepatitis C, and Lassa fever. Moreover, to control the spread of COVID-19, the consumption of antiviral medicines, including RIB, has increased significantly worldwide. By combining ordered mesoporous carbon with silica nanoparticles via ultrasound, we synthesized silica/ordered mesoporous carbon (SiO2-OMC) hybrid composites that show excellent electrochemical performance. The hybrid composite was found to contain spherical SiO2 nanoparticles having diameters ranging from 21 to 29 nm. A sensor comprising a carbon paste electrode and SiO2-OMC (SiO2-OMC/CPE) facilitated the ultrasensitive and selective detection of RIB at an oxidation potential of 0.71 V, having a linear range of 0.1-40 μmol L-1, limit of detection of 0.067 μmol L-1, and sensitivity of 1.969 μA μmol-1 L. Furthermore, the results indicate that charge transfer at the interface of the SiO2-OMC hybrid results in a synergistic effect compared to OMC and SiO2 alone. The advantages include the potential for regenerating the sensor surface, rapid and facile production, and suitability for the detection of RIB in capsule, human plasma, and urine samples, making SiO2-OMC/CPE a promising interface for bioelectrochemical applications.

Evaluation of the Correlation Between Climate Change and the Most Reported Cases of Diseases Due to Climate Change in the Study Area Over the Period of 11 Years (2010-2020) in Selected South-Western States (Ekiti, Osun and Ondo), Nigeria.

Climate change, acting via less direct mechanisms, would affect the transmission of many infectious diseases (especially water, food and vector-borne diseases). The aim of this study is to evaluate the correlation between climate change and emerging and re-emerging diseases in selected south-west states (Ekiti, Osun and Ondo) Nigeria. This study covered the entire population of three south western states (Ekiti, Osun and Ondo) and relied more on secondary data from the Health records department (Data Bank) from the Federal Ministries of Health with additional data from NIMET (weather data or reports). Selection of health care facilities in each of the three states, health data indicating disease distribution and records from 2010 -2020 alongside climate data from Ekiti, Osun and Ondo State. An integrated approach using correlation study was employed in assessing the effect of climate change in particular reference to emerging and re-emerging disease in the study areas. Findings revealed that the higher the temperature the higher the emergence of Measles and Chicken pox, but the lower the temperature the higher the emergence of influenza and Pneumonia. The emergence of Lassa Fever however does not depend on the climatic change either with high or low temperature in South-West, Nigeria. Hence it was concluded that there is correlation between climate change and emerging and re-emerging of diseases.

Current state of Lassa fever in Nigeria and its risk of progression into central nervous system disorders

Current state of Lassa fever in Nigeria and its risk of progression into central nervous system disorders

Lassa fever cases and mortality in Nigeria: Quantile Regression vs. Machine Learning Models.

Lassa fever (LF) is caused by the Lassa fever virus (LFV). It is endemic in West Africa, of which % of the infections are ascribed to Nigeria. This disease affects mostly the productive age and hence a proper understanding of the dynamics of this disease will help in formulating policies that would help in curbing the spread of LF. The objective of this study is to compare the performance of quantile regression models with that of Machine Learning models in. Data between between 7th January 2018 2018 and 17th December, 2022 on suspected cases, confirmed cases and deaths resulting from LF were retrieved from the Nigeria Centre for Disease Control (NCDC). The data obtained were fitted to quantile regression models (QRM) at 25, 50 and 75% as well as to Machine learning models. The response variable being confirmed cases and mortality due to Lassa fever in Nigeria while the independent variables were total confirmed cases, the week, month and year. Result showed that the highest monthly mean confirmed cases (56) and mortality (9) from LF were reported in February. The first quarter of the year reported the highest cases of both confirmed cases and deaths in Nigeria. Result also revealed that for the confirmed cases, quantile regression at 50% outperformed the best of the MLM, Gaussian-matern5/2 GPR (RMSE=10.3393 vs. 11.615), while for mortality, the medium Gaussian SVM (RMSE=1.6441 vs. 1.8352) outperformed QRM. Quantile regression model at 50% better captured the dynamics of the confirmed cases of LF in Nigeria while the medium Gaussian SVM better captured the mortality of LF in Nigeria. Among the features selected, confirmed cases was found to be the most important feature that drive its mortality with the implication that as the confirmed cases of Lassa fever increases, is a significant increase in its mortality. This therefore necessitates a need for a better intervention measures that will help curb Lassa fever mortality as a result of the increase in the confirmed cases. There is also a need for promotion of good community hygiene which could include; discouraging rodents from entering homes and putting food in rodent proof containers to avoid contamination to help hart the spread of Lassa fever in Nigeria.

Hand hygiene among oral health care providers in public institutions in Edo state even in the wake of Lassa fever.

Hand hygiene is recognized as the leading measure to prevent the cross-transmission of microorganisms and to reduce the incidence of healthcare-associated infections. To assess the knowledge and practice of hygiene among dental health workers even in the wake of Lassa fever. This questionnaire-based descriptive cross-sectional study was carried out in four public hospitals in Edo state. All data were collected using a self-administered structured questionnaire after obtaining ethical clearance. 108 of the 120 questionnaires distributed were filled and returned giving a response rate of 90.0%. Overall assessment of respondents' knowledge of hand hygiene revealed that 41.7% of the respondents possessed a good knowledge of hand hygiene, 37.0% had excellent knowledge, 17.6% had moderate and 3.7% had a weak knowledge of hand hygiene. Overall assessment of the practice of hand hygiene showed that the hand hygiene practice of 58.3% of respondents was fair while 37.0% practiced hand hygiene poorly. Only a few (5.6%) respondents had good hand hygiene practices. The outbreak of Lassa fever does not seem to positively influence the practice of hand hygiene among the respondents. While knowledge of hand hygiene is satisfactory in this study, the practice still leaves much to be desired.

Lassa virus in novel hosts: insights into the epidemiology of lassa virus infections in southern Nigeria

ABSTRACT Identification of the diverse animal hosts responsible for spill-over events from animals to humans is crucial for comprehending the transmission patterns of emerging infectious diseases, which pose significant public health risks. To better characterize potential animal hosts of Lassa virus (LASV), we assessed domestic and non-domestic animals from 2021–2022 in four locations in southern Nigeria with reported cases of Lassa fever (LF). Birds, lizards, and domestic mammals (dogs, pigs, cattle and goats) were screened using RT-qPCR, and whole genome sequencing was performed for lineage identification on selected LASV positive samples. Animals were also screened for exposure to LASV by enzyme-linked immunosorbent assay (ELISA). Among these animals, lizards had the highest positivity rate by PCR. Genomic sequencing of samples in most infected animals showed sub-lineage 2 g of LASV. Seropositivity was highest among cattle and lowest in pigs. Though the specific impact these additional hosts may have in the broader virus-host context are still unknown – specifically relating to pathogen diversity, evolution, and transmission – the detection of LASV in non-rodent hosts living in proximity to confirmed human LF cases suggests their involvement during transmission as potential reservoirs. Additional epidemiological data comparing viral genomes from humans and animals, as well as those circulating within the environment will be critical in understanding LASV transmission dynamics and will ultimately guide the development of countermeasures for this zoonotic health threat.

Awareness of Lassa Fever among Rural Dwellers of Ebonyi State

Awareness of Lassa Fever among Rural Dwellers of Ebonyi State

Knowledge and practices associated with Lassa fever in rural Nigeria: Implications for prevention and control.

Lassa fever (LF) is a haemorrhagic illness endemic in West Africa, which can be attributed to poor rat control and poor sanitation, especially in the rural communities. Increasing awareness and education about LF has been advocated for its prevention and control. This study investigated the level of awareness and knowledge associated with LF among the residents of Iwo and Oluponna areas of Osun State, southwest Nigeria. A descriptive cross-sectional study was carried out among the adult residents using a structured questionnaire. Descriptive and inferential statistics were used in analysing the data. In total, 534 (79.11%) respondents had heard about LF, but only 15.4% had good knowledge of the disease. Their main source of information was the media (46.3%, P=0.002, P<0.01), while only 21.2% got information from health workers. About 45% of respondents have rats in their houses. Respondents from Iwo were better informed than Oluponna. Multiple logistic regression analysis indicated location to be significantly associated with awareness (OR=1.62, C.I=1.078-2.433, P<0.05), knowledge of prevention (OR=5.88, C.I=2.807-12.317, P=0.000, P<0.01) and treatment (OR=1.648, C.I=1.122-2.420, P=0.011, P<0.05). Although the residents of Iwo are better informed about LF than Oluponna residents, the knowledge of the disease is poor in both areas. Health workers should be well informed, and the government should increase enlightenment programmes about LF, especially in rural communities of Nigeria, so as to curtail the spread and prevent outbreaks.

Determinants of knowledge on Lassa hemorrhagic fever among medical students at the Faculty of Health Sciences at Cotonou in Benin

Determinants of knowledge on Lassa hemorrhagic fever among medical students at the Faculty of Health Sciences at Cotonou in Benin

Ecological correlates and predictors of Lassa fever incidence in Ondo State, Nigeria 2017–2021: an emerging urban trend

Lassa fever (LF) is prevalent in many West African countries, including Nigeria. Efforts to combat LF have primarily focused on rural areas where interactions between rodents and humans are common. However, recent studies indicate a shift in its occurrence from rural to urban areas. We analysed secondary data of reported LF outbreaks from 2017 to 2021 in Ondo State, Nigeria to identify the distribution pattern, ecological variations, and other determinants of disease spread from the ward level using nearest neighbour statistics and regression analysis. Data utilised include LF incidence, ecological variables involving population, nighttime light intensity, vegetation, temperature, market presence, road length, and building area coverage. ArcGIS Pro 3.0 software was employed for spatial analysis. Results revealed spatio-temporal clustering of LF incidents between 2017 and 2021, with an increasing trend followed by a decline in 2021. All wards in Owo Local Government Area were identified as LF hotspots. The ecological variables exhibited significant correlations with the number of LF cases in the wards, except for maximum temperature. Notably, these variables varied significantly between wards with confirmed LF and those without. Therefore, it is important to prioritise strategies for mitigating LF outbreaks in urban areas of Nigeria and other LF-endemic countries.

Government Administrative Practices and Spread of COVID-19 in Akwa Ibom State, Nigeria

This study examined government administrative practices and the spread of COVID-19 in Akwa Ibom State, Nigeria, employing a survey research design. The study sought to ascertain the effect of lockdown and quarantine as administrative practices on the spread of COVID-19 in Akwa Ibom State. Data were collected from three hospitals, one from each of the three senatorial districts of the state. A descriptive research design was adopted to review data, using the Statistical Package for Social Science (SPSS) version 25. The Emergency management theory was reviewed as a basis for the explanation of concepts for the study. The findings of the study revealed a significant effect of lockdown administrative practices on reducing the spread of COVID-19, while quarantine administrative practices indicated an insignificant impact on the spread of COVID-19 in Akwa Ibom State. It was concluded that the use of lockdown and quarantine were useful administrative instruments for curtailing the spread of COVID-19 in Akwa Ibom State. The study therefore recommended that lockdown should be used in disease-endemic areas in Akwa Ibom state, especially in areas with high infection rates for Lassa fever and others. This would help curb infections like coronavirus. Also. there is a need for the government to retain all the activated quarantine centres for healthcare purposes if another pandemic occurs. This will reinforce the preventive capacity of the government to deal with such.

Modelling seasonality of Lassa fever incidences and vector dynamics in Nigeria.

Lassa fever (Lf) is a viral haemorrhagic disease endemic to West Africa and is caused by the Lassa mammarenavirus. The rodent Mastomys natalensis serves as the primary reservoir and its ecology and behaviour have been linked to the distinct spatial and temporal patterns in the incidence of Lf. Nigeria has experienced an unprecedented epidemic that lasted from January until April of 2018, which has been followed by subsequent epidemics of Lf in the same period every year since. While previous research has modelled the case seasonality within Nigeria, this did not capture the seasonal variation in the reproduction of the zoonotic reservoir and its effect on case numbers. To this end, we introduce an approximate Bayesian computation scheme to fit our model to the case data from 2018-2020 supplied by the NCDC. In this study we used a periodically forced seasonal nonautonomous system of ordinary differential equations as a vector model to demonstrate that the population dynamics of the rodent reservoir may be responsible for the spikes in the number of observed cases in humans. The results show that in December through to March, spillover from the zoonotic reservoir drastically increases and spreads the virus to the people of Nigeria. Therefore to effectively combat Lf, attention and efforts should be concentrated during this period.

Comparative Analysis of Mortality Predictions from Lassa Fever in Nigeria: A Study Using Count Regression and Machine Learning Methods

Comparative Analysis of Mortality Predictions from Lassa Fever in Nigeria: A Study Using Count Regression and Machine Learning Methods

Current sampling and sequencing biases of Lassa mammarenavirus limit inference from phylogeography and molecular epidemiology in Lassa fever endemic regions

Lassa fever (LF) is a potentially lethal viral haemorrhagic infection of humans caused by Lassa mammarenavirus (LASV). It is an important endemic zoonotic disease in West Africa with growing evidence for increasing frequency and sizes of outbreaks. Phylogeographic and molecular epidemiology methods have projected expansion of the Lassa fever endemic zone in the context of future global change. The Natal multimammate mouse (Mastomys natalensis) is the predominant LASV reservoir, with few studies investigating the role of other animal species. To explore host sequencing biases, all LASV nucleotide sequences and associated metadata available on GenBank (n = 2,298) were retrieved. Most data originated from Nigeria (54%), Guinea (20%) and Sierra Leone (14%). Data from non-human hosts (n = 703) were limited and only 69 sequences encompassed complete genes. We found a strong positive correlation between the number of confirmed human cases and sequences at the country level (r = 0.93 (95% Confidence Interval = 0.71–0.98), p &lt; 0.001) but no correlation exists between confirmed cases and the number of available rodent sequences (r = -0.019 (95% C.I. -0.71–0.69), p = 0.96). Spatial modelling of sequencing effort highlighted current biases in locations of available sequences, with increased sequencing effort observed in Southern Guinea and Southern Nigeria. Phylogenetic analyses showed geographic clustering of LASV lineages, suggestive of isolated events of human-to-rodent transmission and the emergence of currently circulating strains of LASV from the year 1498 in Nigeria. Overall, the current study highlights significant geographic limitations in LASV surveillance, particularly, in non-human hosts. Further investigation of the non-human reservoir of LASV, alongside expanded surveillance, are required for precise characterisation of the emergence and dispersal of LASV. Accurate surveillance of LASV circulation in non-human hosts is vital to guide early detection and initiation of public health interventions for future Lassa fever outbreaks.

Environmental Persistence and Disinfection of Lassa Virus.

Lassa fever, caused by Lassa virus (LASV), is endemic to West Africa, where ≈300,000 illnesses and ≈5,000 deaths occur annually. LASV is primarily spread by infected multimammate rats via urine and fomites, highlighting the need to understand the environmental fate of LASV. We evaluated persistence of LASV Josiah and Sauerwald strains on surfaces, in aqueous solutions, and with sodium hypochlorite disinfection. Tested strains were more stable in deionized water (first-order rate constant [k] for Josiah, 0.23 days; for Sauerwald, k = 0.34 days) than primary influent wastewater (Josiah, k=1.3 days; Sauerwald, k = 1.9 days). Both strains had similar decay rates on high-density polyethylene (Josiah, k=4.3 days; Sauerwald, k = 2.3 days) and stainless steel (Josiah, k=5.3 days; Sauerwald, k = 2.7 days). Sodium hypochlorite was highly effective at inactivating both strains. Our findings can inform future risk assessment and management efforts for Lassa fever.

Recent advances in the development of vaccines against hemorrhagic fevers caused by arenaviruses

Arenaviruses are a global threat, causing thousands of deaths each year in several countries around the world. Despite strong efforts in the development of vaccine candidates, vaccines against Lassa fever or Bolivian and Venezuelan hemorrhagic fevers are yet to be licensed for a use in humans. In this synthesis, we present the arenaviruses causing fatal diseases in humans and the main vaccine candidates that have been developed over the past decades with an emphasis on the measles-Lassa vaccine, the first Lassa vaccine ever tested in humans, and on the MOPEVAC platform that can potentially be used as a pan-arenavirus vaccine platform.

Lassa fever and carcinogenesis: emerging as new areas of concern in clinical surgery

Lassa fever and carcinogenesis: emerging as new areas of concern in clinical surgery

A51Educational effectiveness of a high-consequence infectious disease training course using ultraviolet simulation

High-consequence infectious diseases (HCID) are pathogens which spread easily between people, have high mortality rates, and lack effective treatment [1]. Examples include Ebola and Lassa fever. Most emerging pandemics, including COVID-19, are initially classified as HCID. Assessment of patients with suspected HCID infection is an advanced procedural skill requiring application of enhanced infection control measures including patient isolation, personal protective equipment, and decontamination. There is a risk of healthcare worker infection if procedures are not followed [2]. HCID often present in non-specialist centres; there is a need for an accessible, educationally effective HCID course for NHS staff. We developed a course for clinicians in infectious disease and emergency medicine, in collaboration with the Health &amp; Safety Executive and clinicians in the UK-HCID network. The course uses a blended approach; theoretical components are taught with online learning. Practical components are taught with high-fidelity, multidisciplinary simulation using VIOLET, a mannequin which coughs, vomits and sweats ultraviolet markers ( Ultraviolet tracers are used to replicate contact and airborne transmission of infectious pathogens in simulation scenarios Between 01/12/22 and 01/04/23, 57 specialized clinicians participated. All participants passed post-course competency-based practical assessments. Participants demonstrated significant gains in knowledge between pre- and post-course tests (mean score 61% vs. 83%, This is the first HCID simulation course internationally using ultraviolet markers to allow visualization of contamination. The course appears to be an effective educational intervention and improves learner confidence in PPE use. Authors confirm that all relevant ethical standards for research conduct and dissemination have been met. The submitting author confirms that relevant ethical approval was granted, if applicable.

Geometry optimization, impact of solvation on the spectral (FT-IR, UV, NMR) analysis, Quantum chemical parameters, and the bioactivity of feruloyltyramine as a potential anti-Lassa virus agent via molecular docking

The unrelenting menace of the Lassa virus, characterized by its high mortality rate and the potential for global dissemination, underscores an urgent call for its comprehensive eradication to safeguard global public health. In light of this, this research embarked on an extensive investigation of trans-N-feruloyltyramine (FLTM), a compound derived from Cissampelos pareira. This study encompassed a thorough examination of its structural characteristics, utilizing spectroscopic analyses including FT-IR, UV, and NMR, with the aim of elucidating its electronic, structural, and biological properties. Seamlessly integrating experimental and theoretical approaches at the DFT/B3LYP/def2SVP level of theory in FLTM_dmso, FLTM_gas, FLTM_H2O, and FLTM_MeOH solvation. Moreover, solvation dynamic simulation highlighted FLTM's heightened total energy and enhanced solubility across dimethyl sulfoxide (DMSO), water (H2O), and methanol (MeOH) phases, signifying efficient distribution to target sites and emphasizing its potential as a drug candidate. Conversely, FLTM_gas exhibited lower total energy. Electronic properties further elucidated FLTM's reactivity and kinetic stability, with FLTM_DMSO displaying the lowest energy gap among solvents and corresponding values of 1.4168, 4.2159, 4.2175, and 4.2749 eV. These findings mirrored the compound's higher reactivity and lower kinetic stability compared to FLTM_H2O, FLTM_gas, and FLTM_MeOH, aligning with principles of chemical hardness and softness. Results of the molecular docking introduced FLTM as a potential Lassa fever treatment candidate, surpassing Ribavirin in binding affinities with Lassa virus target receptors. FLTM exhibited binding energies of -6.5 kcal/mol, -7.2 kcal/mol, and -8.2 kcal/mol in 7UOT, 3MX5, and 3MX2, respectively, establishing interactions with crucial amino acid residues. These findings strongly advocate for FLTM's efficacy, meriting further in vitro and in vivo investigations for clinical validation.

Re-emergence of Lassa fever in Nigeria: A new challenge for public health authorities.

The Lassa virus is an RNA virus belonging to the Arenaviridae family. It is responsible for Lassa fever, an acute viral zoonosis of the severe hemorrhagic fever type with manifestations of fever, muscle pain, sore throat, nausea, vomiting, and chest and abdominal pain. Lassa fever is endemic in West Africa, where the first case was reported in 1969 in Lassa, a town in Nigeria, more than 50 years ago, and it is estimated that nearly 5000 deaths occur in West Africa each year. Nigeria is one of the endemic hotspots and has experienced numerous recurrent outbreaks of Lassa fever due to the increased multiplication of the host reservoir, Mastomys natalensis. For the Lassa epidemics in 2022 and January 2023 alone, Nigeria accounts for a quarter of the annual deaths from this disease. Poor lifestyle and hygiene, difficulty in diagnosis due to nonspecific symptomatology, lack of effective treatment based on clinical evidence, an ineffective human immunization program combined with a health system that is not adapted or equipped to control and prevent recurrent deadly epidemics, and an outdated regional disease surveillance system in West Africa are some of the challenges that must be overcome to rapidly and effectively eradicate this disease, whose area of spread is constantly expanding as a result of the movement of populations in the context of economic and socio-cultural activities.